This invention relates to apparatus for spinning textile fibers comprising two closely spaced apart, perforated suction drums, which rotate in the same sense and define between them a triangular region, which is adjoined by the suction zones, which face each other, in which apparatus the fibers are received in a flying state by the triangular region and are twisted together therein to form a yarn, which is withdrawn toward one end of the drums and is held against rotation at the same time.
Such apparatus is known, e.g., from Opened German Specification No. 2,449,583. It has been found that it would be desirable to supply the fibers which fly into the triangular region between the suction drums in such an orientation that said fibers are as nearly parallel to each other as possible and extend in the direction in which the yarn is withdrawn because the fibers would then be twisted together in linear contact with each other whereas fibers which cross each other are twisted together only in point contact with each other. A twisting of fibers in linear contact with each other results in a more coherent yarn and is opposed by a smaller resistance so that the yarn can be withdrawn at higher speed. Whereas the simplest and most favorable mode of supplying the fibers is to cause them to fly from a horizontal carding drum, as has been disclosed, e.g., in Opened German Patent Specification No. 2,361,313, in that case the desired parallel orientation of the fibers during the formation of the yarn cannot be accomplished.
When fibrous feed material is disintegrated by a carding drum, the fibers at the periphery of the carding drum will have an orientation transverse to the axis of the drum. This orientation is inherently unfavorable for the subsequent spinning. As the fibers fly from the carding drum into the triangular region between the suction drums, the fibers change their orientation in quite different ways so that part of the fibers enter the triangular region with an orientation which is parallel to the direction in which the fibers are withdrawn, another part of the fibers are oriented transversely to that direction, and a still further part are oriented at different oblique angles to the direction in which the yarn is withdrawn when the fibers reach the actual spinning region.
For this reason it is an object of the invention so to improve the apparatus which has been described first hereinbefore that a yarn can be manufactured which is more uniform and has a higher tenacity and can be withdrawn at a higher speed.
This object is accomplished according to the invention in that a throwing member is disposed in the flight region flown through by the fibers, which flight region is preferably defined by guide walls, and said throwing member is movable toward the yarn-withdrawing means in a plane that is transverse to the flight direction of the fibers.
The fibers which fly from the carding drum into the triangular region between the suction drums impinge on the throwing member, which imparts to the fibers a momentum toward the yarn-withdrawing means so that the fibers are deflected in the desired sense, regardless of the orientation in which they impinge on the throwing member, and the fibers have a substantially parallel orientation as they enter the zone in which the yarn is actually formed. As a result, the fibers have in the triangular region between the suction drums an orientation which is much more favorable than before so that the fibers in the yarn are not only in point contact but contact each other in a larger length. As a result, the coherence and with it the tenacity of the yarn is improved, the resistance to twisting presented by the fibers is reduced and, consequently, the yarn can be withdrawn at higher speed. Besides, the throwing member causes the fibers to be distributed in the triangular region over a larger length in the direction in which the yarn is withdrawn than in the previous practice so that a more uniform yarn results.
In an arrangement which is particularly simple and suitable and can easily be embodied, the throwing member consists of a rotating throwing disc and only a peripheral segment of said disc protrudes into the region flown through by the fibers. It will be understood that fibers impinging on a rotating disc will fly in a tangential direction from said disc. Because the fibers impinge on the disc only in a segmental area, the tangential direction differs only slightly from the direction in which the yarn is withdrawn. Instead of a rotating throwing member, a member which moves along a straight line at least in the flight region flown through by the fibers could be used and could consist e.g., of one course of an endless chain or endless belt and may be provided with flights which extend into the flight region.
To increase the intended action of the throwing disc, the same may be serrated at its periphery, preferably by a provision of saw teeth. If the root circle of such throwing disc remains outside the flight region flown through by the fibers, the flying fibers approaching the disc will strike only on the teeth and will be thrown off with an increased momentum from the sides of the teeth.